In the field of radiofrequency antennas, it is well known to use orthogonal-mode junction couplers, or “ortho-mode junction” (OMJ) couplers, to separate dual-polarization bands.
For medium to broad operating band frequencies, these orthogonal-mode junction couplers are traditionally made up of a supply section of the waveguide comprising orthogonal supply points placed along the axis of the coupler, the points being offset along the axis of the coupler. The supply points are generally realized using connectors, grooves or any other equivalent means well known by One Skilled in the Art.
This type of coupler has the drawback of providing poor isolation between the various inlet ports of the supply points which are close to each other.
Furthermore, this type of coupler has an asymmetry which leads to degradation of the purity of the modal network due to the excitation of higher order modes.
In order to offset the coupling appearing between the different inlet ports of these couplers, it is well known to use an external compensating circuit ensuring supplying of the inlet ports. However, these compensating circuits do not allow the elimination of all errors.